Results 41 to 50 of about 45,362 (276)

Heterogeneous Catalysts in Pictet-Spengler-Type Reactions

Journal of Chemistry, 2013
Several solid catalysts were evaluated as an alternative for 1,2,3,4-tetrahydroisoquinoline synthesis by means of the Pictet-Spengler reaction. The reaction catalysed by a mixed oxide (Mg and Al) led to the best yield and good regioselectivity; using an ...
Rodolfo Quevedo, Camilo Perdomo, Sonia Moreno   +2 more
doaj   +1 more source

A Straightforward Selective Acylation of Phenols over ZSM-5 towards Making Paracetamol Precursors

Bulletin of Chemical Reaction Engineering & Catalysis, 2018
Commercially available ZSM-5 was minimally treated as the catalyst to selectively acylate phenols. The ZSM-5 was simply immersed in ammonium nitrate in order to fill the pores with Brönsted acid to concentrate the catalytic reactions inside the pores ...
Robby Roswanda, Alfhons Daniel Sirampun, Rino Rakhmata Mukti, Didin Mujahidin   +3 more
doaj   +1 more source

Exploring the Uncharted Indolizine Chemical Space: Construction of 5‐Acylindolizines via a Domino Aldol–Vinylogous Aldol Process

Advanced Synthesis &Catalysis, EarlyView.
A domino aldol condensation–intramolecular vinylogous aldol condensation process was implemented for the first time to enable access to a wide range of novel 5‐acylated indolizines with a hydrogen, an alkyl, an aryl, or an alkoxy moiety at the C7 site.
Dohui Ku, Sunhee Lee, Ikyon Kim
wiley   +1 more source

Biocatalytic Regioselective C‐Formylation of Resorcinol Derivatives

Angewandte Chemie, EarlyView.
An acyltransferase from Chromobacterium sphagni (CsATase) was identified that catalyzes the regioselective formylation of resorcinol substrates. The formylation of substituted resorcinol derivatives yielded mono‐formylated products with up to 99% conversion and up to 74% isolated yield.
Lilla Gal, Suresh Rohan, Anna Żądło‐Dobrowolska, Bianca Hilweg, Judith Müller, Kai Tittmann, Wolfgang Kroutil   +6 more
wiley   +2 more sources

Ligand-controlled regiodivergent arylation of aryl(alkyl)alkynes and asymmetric synthesis of axially chiral 9-alkylidene-9,10-dihydroanthracenes

Nature Communications
Transition metal-catalyzed addition of organometallics to aryl(alkyl)alkynes has been well known to proceed with the regioselectivity in forming a carbon–carbon bond at the alkyl-substituted carbon (β-addition).
Chao Sun, Ting Qi, Faiz-Ur Rahman, Tamio Hayashi, Jialin Ming   +4 more
doaj   +1 more source

Regioselective Dimetallapolycarbyl Hydrometalation

Organometallics, 2005
The reactions of [L(CO) 2 W≡CC≡CC≡CC≡ W(CO) 2 L] (L = HB(pz) 3 , HB(pz') 3 ; pz = pyrazol-1-yl, pz' = 3,5-dimethylpyrazol-1-yl) with [RuHCl(CO)(PPh 3 ) 3 ] result in regioselective hydroruthenation of one C≡C bond of the WC 6 W spine to provide the coordinatively unsaturated hex-2-en-4-yn-3-yl-1,6-diylidyne-bridged complex[Ru{C(CS≡CC≡W(CO) 2 L)=CHC≡W ...
Dewhurst, Rian, Hill, Anthony, Smith, Matthew   +2 more
openaire   +2 more sources

Nanoconfinement‐Steered Molecular Preorganization Enables Efficient Monoethanolamine Degradation through Electronically Modulated High‐Valent Iron–Oxo Pathways

Advanced Science, EarlyView.
Precise modulation of reaction pathways remains an unresolved challenge in peroxymonosulfate‐activated advanced oxidation processes. The spatial preorganization strategy in engineered confinement architecture enables regioselective bond cleavage in monoethanolamine via synergistic proton–electron transfer, redirecting its degradation from nonselective ...
Lin Zhang, Qin Dai, Xinyue Chen, Hang Yuan, Lei Xing, Zhimo Fang, Xiuze Li, Xiangke Wang, Lihui Zhang, Junping Zhao, Qiangwei Li, Lidong Wang   +11 more
wiley   +1 more source

Stereospecific Transition‐Metal‐Free Alkylation of Chiral Non‐Racemic Secondary Tosylates with Cyanohydrins: Convenient Access to Enantiomerically Enriched α‐Tertiary Ketones

Angewandte Chemie, EarlyView.
A stereospecific, transition‐metal‐free SN2 alkylation of cyanohydrins with chiral non‐racemic secondary tosylates is reported, providing efficient access to enantioenriched α‐tertiary ketones. The method exhibits broad substrate scope, operational simplicity, and excellent stereospecificity, including stereoconvergent reactions of E/Z mixtures of ...
Jinjin Ma, Hui Li, Jadab Majhi, P. Andrew Evans   +3 more
wiley   +2 more sources

Triplet Energy Transfer‐Driven Intermolecular [2+2] Photocycloaddition of Acyclic Imines and Indoles: Facile Access to Azetidine‐Fused Indolines

Advanced Science, EarlyView.
An intermolecular aza‐Paternò‐Büchi reaction of indoles and acyclic imines is enabled by visible‐light‐driven triplet energy transfer, providing azetidine‐fused indolines up to 93% yield for 30 examples and providing a novel protocol to access previously inaccessible scaffolds. ABSTRACT Currently, successful examples of the aza‐[2+2] photocycloaddition
Gang Yang, Zeng Han, Hong Zhang, Xiuling Cui   +3 more
wiley   +1 more source

(Poly)Borylated Species as Modern Reactive Groups toward Unusual Synthetic Applications

Angewandte Chemie, EarlyView.
In this review, we spotlight recent breakthroughs in α‐polyboron‐substituted carbon‐centered intermediates (carbanion, carbocation, radical, and carbene) and polyborylated alkenes. By bridging fundamental reactivity with the application potential of these extraordinary species, we hope this review will serve as a roadmap for harnessing these unique ...
Nadim Eghbarieh, Nicole Hanania, Pinaki Nad, Tipu Alam, Tamir Kish, Ahmad Masarwa   +5 more
wiley   +2 more sources